Easily Obtaining Excellent Performance High-voltage LiCoO₂ via Pr₆O₁₁ Modification

Developing an effective method to synthesize high-performance high-voltage LiCoO₂ is essential for its industrialization in lithium batteries (LIBs). This work proposes a simple mass-produced strategy for the first time, that is, negative temperature coefficient thermosensitive Pr₆O₁₁ nanoparticles are uniformly modified on LiCoO₂ to prepare LiCoO₂@Pr₆O₁₁ (LCO@PrO) via a liquid-phase mixing combined with annealing method. Tested at 274 mA g⁻¹, the modified LCO@PrO electrodes deliver excellent 4.5 V high-voltage cycling performance with capacity retention ratios of 90.8% and 80.5% at 25 and 60 ℃, being much larger than those of 22.8% and 63.2% for bare LCO electrodes. Several effective strategies were used to clearly unveil the performance enhancement mechanism induced by Pr₆O₁₁ modification. It is discovered that Pr₆O₁₁ can improve interface compatibility, exhibit improved conductivity at elevated temperature, thus enhance the Li⁺ diffusion kinetics, and suppress the phase transformation of LCO and its resulting mechanical stresses. The 450 mAh LCO@PrO‖graphite pouch cells show excellent LIB performance and improved thermal safety characteristics. Importantly, the energy density of such pouch cell was increased even by ~42% at 5 C. This extremely convenient technology is feasible for producing high-energy density LIBs with negligible cost increase, undoubtedly providing important academic inspiration for industrialization.